Front end circuit, module, and communication device

ABSTRACT

A front end circuit includes: a first antenna terminal from/to which transmission/reception signals of a low band (LB) and a high band (HB); a second antenna terminal from/to which a transmission/reception signal of a middle band (MB) is output/input; an LB terminal to/from which the transmission/reception signal of the LB is input/output, an MB terminal to/from which the transmission/reception signal of the MB is input/output; an HB terminal to/from which the transmission/reception signal of the HB is input/output; and a separating circuit that passes the transmission and reception signals of the LB and suppresses the transmission and reception signals of the MB and the HB between the first antenna terminal and the LB terminal, and that passes the transmission and reception signals of the HB and suppresses the transmission and reception signals of the LB and the MB between the first antenna terminal and the HB terminal.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority of theprior Japanese Patent Application No. 2015-090663, filed on Apr. 27,2015, and the prior Japanese Patent Application No. 2015-157557, filedon Aug. 7, 2015, the entire contents of which are incorporated herein byreference.

FIELD

A certain aspect of the present invention relates to a front endcircuit, a module, and a communication device.

BACKGROUND

Signals of multiple bands may be transmitted and received in wirelesscommunication devices such as mobile phone terminals. For example, LTE(Long Term Evolution) or the like uses bands including a low band of 1GHz or lower, a middle band around 2 GHz, and a high band around 2.5GHz. Each of the low band, the middle band, and the high band includestwo or more bands each including a transmit band and a receive band.

Sharing an antenna terminal between the low band and the middle bandwith use of a diplexer is disclosed in Japanese Patent ApplicationPublication No. 2014-526847 (Patent Document 1), U.S. Patent ApplicationPublication No. 2006/0128393 (Patent Document 2), and InternationalPublication No. 2012/093539 (Patent Document 3). Patent Document 2discloses an art that uses individual antenna terminals for the lowband, the middle band, and the high band. Patent Document 3 discloses anarrangement of filters for two or more bands.

When separate antenna terminals are provided as described in PatentDocuments 1, 2, the interference between the bands is reduced (forexample, the isolation is improved), but three connectors for RF (RadioFrequency) are required, and thus the cost and the size increase. On theother hand, when the antenna terminal is shared, the cost and the sizecan be reduced, but the interference between the bands increases. Forexample, when three antenna terminals are unified to be a shared singleantenna, the number of required RF connectors becomes one, but the lossof a multiplexer and/or the interference between the bands increases.Moreover, the methods disclosed in Patent Documents 1 through 3 fail tosufficiently reduce the interference between the bands.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, there is provided afront end circuit including: a first antenna terminal that is coupled toa first antenna, from which transmission signals of a low band and ahigh band are output, and to which reception signals of the low band andthe high band are input, frequency of the high band being higher thanfrequency of the low band; a second antenna terminal that is coupled toa second antenna different from the first antenna, from which atransmission signal of a middle band is output, and to which a receptionsignal of the middle band is input, frequency of the middle band beinghigher than the frequency of the low band and being lower than thefrequency of the high band; a low band terminal to which thetransmission signal of the low band is input, and from which thereception signal of the low band is output; a middle band terminal towhich the transmission signal of the middle band is input, and fromwhich the reception signal of the middle band is output; a high bandterminal to which the transmission signal of the high band is input, andfrom which the reception signal of the high band is output; and aseparating circuit that passes the transmission signal and the receptionsignal of the low band between the first antenna terminal and the lowband terminal, suppresses the transmission signal and the receptionsignal of the middle band and the transmission signal and the receptionsignal of the high band between the first antenna terminal and the lowband terminal, passes the transmission signal and the reception signalof the high band between the first antenna terminal and the high bandterminal, and suppresses the transmission signal and the receptionsignal of the low band and the transmission signal and the receptionsignal of the middle band between the first antenna terminal and thehigh band terminal.

According to another aspect of the present invention, there is provideda module including: the above front end circuit.

According to another aspect of the present invention, there is provideda communication device including: the above front end circuit.

According to another aspect of the present invention, there is provideda module including: a first transmit filter that passes a transmissionsignal of a first band; a first receive filter that passes a receptionsignal of the first band; a second transmit filter that passes atransmission signal of a second band; a second receive filter thatpasses a reception signal of the second band; a third transmit filterthat passes a transmission signal of a third band; and a third receivefilter that passes a reception signal of the third band, wherein atransmit band of the first band overlaps with at least a part of areceive band of the second band, a receive band of the third band doesnot overlap with the transmit band of the first band or a transmit bandof the second band, and the third receive filter is located between thefirst receive filter and the second receive filter.

According to another aspect of the present invention, there is provideda module including: a first transmit filter that passes a transmissionsignal of a first band; a first receive filter that passes a receptionsignal of the first band; a second transmit filter that passes atransmission signal of a second band; a second receive filter thatpasses a reception signal of the second band; a third transmit filterthat passes a transmission signal of a third band; a third receivefilter that passes a reception signal of the third band; a fourthtransmit filter that passes a transmission signal of a fourth band; anda fourth receive filter that passes a reception signal of the fourthband, wherein the reception signal of the first band and the receptionsignal of the second band are simultaneously received, a receive band ofthe third band overlaps with at least a part of a transmit band of thefirst band; a receive band of the fourth band does not overlap with thetransmit band of the first band or a transmit band of the second band,and the fourth receive filter is located between the second receivefilter and the third receive filter.

According to another aspect of the present invention, there is provideda module including: at least three first filters that are connectedbetween one first common terminal and a corresponding one of at leastthree first terminals, and have different passbands; at least one secondfilter that is connected between one second common terminal and at leastone second terminal; a first wiring line that connects the one firstcommon terminal to the at least three first filters; and a second wiringline that connects the one second common terminal to the at least onesecond filter, wherein the first common terminal and the second commonterminal are located at a same side as the at least three first filters,the at least one second filter is opposite the first common terminal andthe second common terminal across the at least three first filters, andthe second wiring line intersects with the first wiring line only in asingle region.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a transmit band and a receive band of each of bandsused in first through fifth embodiments;

FIG. 2 is a circuit diagram of a front end circuit in accordance withthe first embodiment;

FIG. 3 is a circuit diagram of a front end circuit in accordance with afirst comparative example;

FIG. 4 is a circuit diagram of a front end circuit in accordance with asecond comparative example;

FIG. 5A is a block diagram of a diplexer in accordance with the firstcomparative example, and FIG. 5B illustrates the frequencycharacteristic of the diplexer;

FIG. 6A is a block diagram of a diplexer in accordance with the firstembodiment, and FIG. 6B illustrates the frequency characteristic of thediplexer;

FIG. 7 is a circuit diagram of a front end circuit in accordance withthe second embodiment;

FIG. 8 is a circuit diagram of a front end circuit in accordance with afirst variation of the second embodiment;

FIG. 9 is a circuit diagram of a front end circuit in accordance with asecond variation of the second embodiment;

FIG. 10A through FIG. 10D are circuit diagrams illustrating otherexamples of a separating circuit in the second variation of the secondembodiment;

FIG. 11 is a circuit diagram of a middle band circuit in the thirdembodiment;

FIG. 12A and FIG. 12B illustrate a module in accordance with a thirdcomparative example;

FIG. 13 is a schematic plan view illustrating a module in accordancewith the third embodiment;

FIG. 14 is a schematic plan view illustrating a module in accordancewith a first variation of the third embodiment;

FIG. 15 is a schematic plan view illustrating a module in accordancewith a second variation of the third embodiment;

FIG. 16 is a circuit diagram of a middle band circuit in a thirdvariation of the third embodiment;

FIG. 17 is a schematic plan view illustrating a module in accordancewith the third variation of the third embodiment;

FIG. 18 is a circuit diagram of a low band circuit in a fourth variationof the third embodiment;

FIG. 19 is a schematic plan view illustrating a module in accordancewith a fourth comparative example;

FIG. 20 is a schematic plan view illustrating a module in accordancewith the fourth variation of the third embodiment;

FIG. 21 is a schematic plan view illustrating another module inaccordance with the third variation of the third embodiment;

FIG. 22 is a schematic plan view illustrating a module in accordancewith the fourth embodiment;

FIG. 23 is a schematic plan view illustrating a module in accordancewith a first variation of the fourth embodiment;

FIG. 24 is a schematic plan view illustrating a module in accordancewith a second variation of the fourth embodiment;

FIG. 25 is a schematic plan view illustrating another module inaccordance with the fourth variation of the third embodiment;

FIG. 26 is a schematic plan view illustrating a module in accordancewith a third variation of the fourth embodiment;

FIG. 27A is a block diagram around an antenna of a communication devicein accordance with the fifth embodiment, and FIG. 27B is a perspectiveview of the antenna;

FIG. 28A is a block diagram around an antenna of a communication devicein accordance with a first variation of the fifth embodiment, and FIG.28B is a perspective view of the antenna;

FIG. 29A is a plan view of the module in accordance with the fourthembodiment, and FIG. 29B is a plan view of a module in accordance with asixth embodiment;

FIG. 30 is a cross-sectional view of the module in accordance with thesixth embodiment;

FIG. 31A and FIG. 31B are plan views of insulating layers in the sixthembodiment (No. 1);

FIG. 32A and FIG. 32B are plan views of insulating layers in the sixthembodiment (No. 2);

FIG. 33 is a plan view of an insulating layer 60 in the fourthembodiment; and

FIG. 34A and FIG. 34B are plan views of insulating layers in a firstvariation of the sixth embodiment.

DETAILED DESCRIPTION

Hereinafter, a description will be given of embodiments with referenceto accompanying drawings. The LTE band used in the embodiments is afrequency band that supports the LTE standard (E-UTRA Operating Band).

First Embodiment

A first embodiment is an exemplary front end circuit that performsso-called carrier aggregation that simultaneously receives receptionsignals of multiple bands and/or simultaneously transmits transmissionsignals of multiple bands. As the multiple bands, used are LTE bands B1,B2 (or B25), B3, B4, B5 (or B26), B7, B8, B12 (or B17), B13, B20, andB30. “B” is affixed to the number indicating the band to distinguishfrom the reference numerals.

FIG. 1 illustrates the transmit band and the receive band of each of thebands used in the first through fifth embodiments. As illustrated inFIG. 1, LTE bands B5, B8, B12, B13, B17, B20, B26, and B29 are lowbands. LTE bands B1 through B4, and B25 are middle bands, and LTE bandsB7 and B30 are high bands.

FIG. 2 is a circuit diagram of a communication device and a front endcircuit in accordance with the first embodiment. The chain lineindicates a line through which a transmission signal is mainlytransmitted, the dashed line indicates a line through which a receptionsignal is mainly transmitted, and the solid line indicates a linethrough which a transmission signal and a reception signal aretransmitted. As illustrated in FIG. 2, a front end circuit 104 mainlyincludes terminals T1 (a first antenna terminal), T2 (a second antennaterminal), TL (a low band terminal), TM (a middle band terminal), and TH(a high band terminal), a diplexer 16, a low band circuit 10L, a middleband circuit 10M, a high band circuit 10H, and an RFIC (Radio FrequencyIntegrated Circuit) 48. The communication device includes the front endcircuit 104, and antennas 40LH and 40M.

The terminal T1 is coupled to the antenna 40LH, and the terminal T2 iscoupled to the antenna 40M. The transmission signal of the low band isinput to the terminal TL, and the reception signal of the low band isoutput from the terminal TL. The transmission signal of the middle bandis input to the terminal TM, and the reception signal of the middle bandis output from the terminal TM. The transmission signal of the high bandis input to the terminal TH, and the reception signal of the high bandis output from the terminal TH. The diplexer 16 is coupled to theterminals T1, TL, and TH. The terminal T2 is coupled to the terminal TM.A tuner 38 a is connected between the terminal T1 and the diplexer 16,and a tuner 38 b is connected between the terminal T2 and the terminalTM. The tuner 38 a matches impedance when the impedance of the antenna40LH changes, and the tuner 38 b matches impedance when the impedance ofthe antenna 40M changes. The tuners 38 a and 38 b may be omitted. Acoupler used to feedback a part of the transmission signal may belocated between the terminal T1 and the diplexer 16 and/or between theterminals T2 and TM.

The diplexer 16 includes a low-pass filter connected between theterminals T1 and TL, and a high-pass filter connected between theterminals T1 and TH. This configuration allows the diplexer 16 to passthe transmission signal and the reception signal of the low band betweenthe terminal T1 and the terminal TL, and suppresses the transmissionsignals and the reception signals of the middle band and the high bandbetween the terminal T1 and the terminal TL. The diplexer 16 passes thetransmission signal and the reception signal of the high band betweenthe terminal T1 and the terminal TH, and suppresses the transmissionsignals and the reception signals of the low band and the middle bandbetween the terminal T1 and the terminal TH.

The terminal TL connects to the low band circuit 10L, the terminal TMconnects to the middle band circuit 10M, and the terminal TH connects tothe high band circuit 10H. The low band circuit 10L, the middle bandcircuit 10M, and the high band circuit 10H connect to the RFIC 48. TheRFIC 48 transmits a transmission signal before amplified to the low bandcircuit 10L, the middle band circuit 10M, and the high band circuit 10H.The RFIC 48 includes a low noise amplifier, and amplifies receptionsignals received from the low band circuit 10L, the middle band circuit10M, and the high band circuit 10H.

The low band circuit 10L includes quadplexers 15 h, 15 i, a switch 20,and power amplifiers 36 b and 36 c. The middle band circuit 10M includesquadplexers 15 c, 15 d, switches 21, 26, and power amplifiers 36 d and36 e. The high band circuit 10H includes a quadplexer 15 e, a switch 29,and a power amplifier 36 f.

The quadplexer 15 h includes a transmit filter 12 and a receive filter14 for LTE band B5/B26, and the transmit filter 12 and the receivefilter 14 for LTE band B12. The filter 12 and the receive filter 14 forLTE band B20. The quadplexer 15 c includes the transmit filter 12 andthe receive filter 14 for LTE band B2, and the transmit filter 12 andthe receive filter 14 for LTE band B4. The quadplexer 15 d includes thetransmit filter 12 and the receive filter 14 for LTE band B1, and thetransmit filter 12 and the receive filter 14 for LTE band B3. Thequadplexer 15 e includes the transmit filter 12 and the receive filter14 for LTE band B7, and the transmit filter 12 and the receive filter 14for LTE band B30.

The transmit filter 12 is a bandpass filter, passes the transmissionsignal in the corresponding band, and suppresses the reception signal.The receive filter 14 is a bandpass filter, passes the reception signalin the corresponding band, and suppresses the transmission signal. Thetransmission band of LTE band B5 overlap with the transmission band ofLTE band B26, and the reception band of LTE band B5 overlap with thereception band of LTE band B26. Thus, the transmit filter 12 and thereceive filter 14 for LTE band B5/B26 can be shared by LTE bands B5 andB26.

The SP3T (Single Pole 3 Throw) switch 20 selects one of the outputs fromthe common terminals of the quadplexers 15 h and 15 i and from the poweramplifier 36 c for GSM (global system for mobile communications)(registered trademark) of the low band, and connects the selected outputto the terminal TL. A transmission signal is output from the RFIC 48 tothe power amplifiers 36 b through 36 f. A SP4T (Single Pole 4 Throw)switch 25 a outputs the output of the power amplifier 36 b to one of thetransmit filters 12 for LTE bands B5/B26, B12, B8, and B20.

The SP3T switch 21 selects one of the outputs from the common terminalsof the quadplexers 15 c and 15 d and from the power amplifier 36 d forGSM (registered trademark) of the high band, and connects the selectedoutput to the terminal TM. A SP4T (Single Pole 4 Throw) switch 26outputs the output of the power amplifier 36 e to one of the transmitfilters 12 for LTE bands B2, B1, B4, and B3. The SPDT switch 29 outputsthe output of the power amplifier 36 f to one of the transmit filters 12for LTE bands B7 and B30.

To explain the advantage of the first embodiment, a description will begiven of comparative examples. FIG. 3 is a circuit diagram of a frontend circuit in accordance with a first comparative example. Asillustrated in FIG. 3, in a front end circuit 110, the terminal T1 iscoupled to an antenna 40LM. The diplexer 16 is connected between theterminal T1 and the terminal TL, and between the terminal T1 and theterminal TM. The terminal T2 is coupled to an antenna 40H. The terminalT2 is coupled to the terminal TH. Instead of the quadplexer 15 e,duplexers 15 f, 15 g and an SPDT switch 28 are provided. Otherconfigurations are the same as those of the first embodiment, and thusthe description thereof is omitted.

FIG. 4 is a circuit diagram of a front end circuit in accordance with asecond comparative example. As illustrated in FIG. 4, in a front endcircuit 112, the terminal T1 is coupled to an antenna 40L and to theterminal TL. The terminal T2 is coupled to the middle band antenna 40Mand to the terminal TM. A terminal T3 is coupled to the antenna 40H andto the terminal TH. Tuners 38 are connected between the antenna 40L andthe terminal TL, between the antenna 40M and the terminal TM, andbetween the antenna 40H and the terminal TH. Other configurations arethe same as those of the first comparative example, and thus thedescription thereof is omitted.

The problem of the first comparative example will be explained. FIG. 5Ais a block diagram of a diplexer in the first comparative example, andFIG. 5B illustrates the frequency characteristic of the diplexer. Asillustrated in FIG. 5A, the diplexer 16 includes a low-pass filter (LPF)16 a and a high-pass filter (HPF) 16 b. The LPF 16 a is connectedbetween the terminals T1 and TL. The HPF 16 b is connected between theterminals T1 and TM. As described above, the first comparative exampleuses the diplexer 16 to separate the low band LB and the middle band MB.As described above, the use of the diplexer 16 allows the antenna to beshared.

As illustrated in FIG. 5B, the low band LB is the passband of the LPF 16a, and is the suppression band of the HPF 16 b. The middle band MB isthe passband of the HPF 16 b, and is the suppression band of the LPF 16a. However, the suppression characteristic of the HPF 16 b in the lowband LB and/or the suppression characteristic of the LPF 16 a in themiddle band MB is not sufficient. Thus, to achieve the sufficientsuppression, the loss of the LPF 16 a in the low band LB and/or the lossof the HPF 16 b in the middle band MB increases. Accordingly, the powerof the transmission signal in the terminals TL and TM needs to beincreased. This increases the electrical power consumption of the poweramplifier. In addition, when the power of the transmission signal islarge, harmonic signals, intermodulation distortion, or/and crossmodulation distortion generated in the power amplifier, the switch, andthe filter for the low band LB increase. They interfere with the middleband MB and/or the high band HB.

Furthermore, the loss of the LPF 16 a in the low band LB and/or the lossof the HPF 16 b in the middle band MB is large. Thus, the level of thereception signal in the terminals TL and TM decreases.

FIG. 6A is a block diagram of the diplexer in the first embodiment, andFIG. 6B illustrates the frequency characteristic of the diplexer. Asillustrated in FIG. 6A, the LPF 16 a is connected between the terminalsT1 and TL. The HPF 16 b is connected between the terminals T1 and TH. Asdescribed above, the first embodiment uses the diplexer 16 to separatethe low band LB and the high band HB.

As illustrated in FIG. 6B, the low band LB is the passband of the LPF 16a, and is the suppression band of the HPF 16 b. The high band HB is thepassband of the HPF 16 b, and is the suppression band of the LPF 16 a.Since the frequency interval between the low band LB and the high bandHB is wide, the suppression characteristic of the HPF 16 b in the lowband LB and the suppression characteristic of the LPF 16 a in the highband HB can be improved. Thus, the loss of the LPF 16 a in the low bandLB and the loss of the HPF 16 b in the high band HB can be reduced.Accordingly, the power of the transmission signal in the terminals TLand TH can be reduced. This decreases the electrical power consumptionof the power amplifier. Moreover, since the power of the transmissionsignal is small, harmonic signals, intermodulation distortion, or/andcross modulation distortion generated in the power amplifier, theswitch, and the filter for the low band LB decrease. Thus, these signalscan be prevented from interfering with the middle band MB and/or thehigh band HB.

Furthermore, the loss of the LPF 16 a in the low band LB and the loss ofthe HPF 16 b in the high band HB can be reduced. Thus, the level of thereception signal in the terminals TL and TH can be increased.

A problem of the second comparative example will be explained. In thesecond comparative example, since the antenna terminal T1 and theantenna 40L are provided for the low band LB, the antenna terminal T2and the antenna 40M are provided for the middle band MB, and the antennaterminal T3 and the antenna 40H are provided for the high band HB, thecost and the size increase. Furthermore, to improve the isolation amongthree antenna terminals T1 through T3 and/or the isolation among threeantennas 40L, 40M, and 40H, the arrangement of the antenna terminals T1through T3 and/or the three antennas 40L, 40M, and 40H becomescomplicated. When it is difficult to arrange the antenna terminalsand/or the antennas, a filter needs to be added, and thus the costfurther increases.

In the first embodiment, the transmission signals of the low band andthe high band are output from the terminal T1, and the reception signalsof the low band and the high band are input to the terminal T1. Theterminal T2 is connected to an antenna different from the antennaconnected to the terminal T1, and the transmission signal of the middleband is output from the terminal T2, and the reception signal of themiddle band is input to the terminal T2. The diplexer 16 is used as aseparating circuit that separates the low band and the high band.

This configuration reduces the number of antenna terminals, and reducesthe number of RF connectors compared to the second comparative examplethat provides three antenna terminals. Thus, the cost and the size canbe reduced. Furthermore, compared to the first comparative example thatuses a separating circuit that separates the low band and the middleband to share an antenna terminal by the low band and the middle band,the electrical power consumption can be reduced, the interference of theharmonic signal, the intermodulation distortion signal, and/or the crossmodulation distortion signal of the low band with the middle band and/orthe high band can be reduced, and the sensitivity of the receptionsignal can be improved.

Second Embodiment

FIG. 7 is a circuit diagram of a front end circuit in accordance withthe second embodiment. As illustrated in FIG. 7, in a front end circuit100, the low band circuit 10L includes multiplexers 15 a, 15 b, switches20, 22 through 24, 30, and the power amplifiers 36 a through 36 c. Themultiplexer 15 a includes the transmit filters 12 and the receivefilters 14 for LTE bands B5/B26, B13, and B29. The multiplexer 15 bincludes the transmit filters 12 and the receive filters 14 for LTEbands B8, B20, and B12.

The SPDT (Single Pole double Throw) switch 22 connects the output of thepower amplifier 36 a to one of the transmit filters 12 for LTE bands B12and B13. A SPDT switch 23 selects one of the outputs from the receivefilters 14 for LTE bands B12 and B5/B26, and outputs the selected outputto the RFIC 48. The SPDT switch 24 selects one of the outputs from thereceive filters 14 for LTE bands B8 and B20, and outputs the selectedoutput to the RFIC 48. A

SP3T switch 25 outputs the output of the power amplifier 36 b to one ofthe transmit filters 12 for LTE bands B5/B26, B8, and B20.

The SPDT switch 30 outputs the output of the RFIC 48 to one of the poweramplifiers 36 b and 36 c. A SPDT switch 31 outputs the output of theRFIC 48 to one of the power amplifiers 36 d and 36 e. Otherconfigurations are the same as those of the first embodiment, and thusthe description thereof is omitted.

FIG. 8 is a circuit diagram of a front end circuit in accordance with afirst variation of the second embodiment. As illustrated in FIG. 8, in afront end circuit 101, the multiplexers 15 a and 15 b are replaced withduplexers, and the quadplexers 15 c through 15 e are replaced withduplexers. Accordingly, the SP3T switch 20 is replaced with amulti-throw RF switch 20 a capable of independently switching ON/OFF,and the SP3T switch 21 is replaced with a multi-throw RF switch 21 acapable of independently switching ON/OFF. The SPDT switch 28 is locatedbetween the terminal TH and the duplexers for LTE bands B30 and B7.Other configurations are the same as those of the second embodimentillustrated in FIG. 7, and thus the description thereof is omitted.

As described in the first variation of the second embodiment, themultiplexers 15 a and 15 b and the quadplexers 15 c through 15 e may bereplaced with duplexers. Moreover, one or more of the multiplexers 15 aand 15 b and the quadplexers 15 c through 15 e may be replaced withduplexers.

FIG. 9 is a circuit diagram of a front end circuit in accordance with asecond variation of the second embodiment. As illustrated in FIG. 9, ina front end circuit 102, instead of the diplexer 16, a separatingcircuit 42 is provided. The separating circuit 42 includes a matchingcircuit 44 and an LPF 46. The matching circuit 44 is located between theterminal T1 and the terminals TL and TH. The LPF 46 is located betweenthe matching circuit 44 and the terminal TL. The separating circuit 42decreases the impedance in the low band when the terminal TL is viewedfrom the terminal T1 side, and increases the impedance in the high band.On the other hand, the separating circuit 42 decreases the impedance inthe high band when the terminal TH is viewed from the terminal T1 side,and increases the impedance in the low band. As described above, theseparating circuit may not be a diplexer.

FIG. 10A through FIG. 10D are circuit diagrams illustrating otherexamples of the separating circuit in the second variation of the secondembodiment. As illustrated in FIG. 10A, matching circuits 43 and 45 maybe located separately at the terminal TL side and at the terminal THside, respectively. As illustrated in FIG. 10B, the LPF 46 may beomitted, and an HPF 47 may be located between the terminal T1 and theterminal TH. As described above, one of the LPF 46 and the HPF 47 may beprovided. As illustrated in FIG. 10C, the LPF 46 and the HPF 47 may beomitted, and only the matching circuit 44 may be provided. Asillustrated in FIG. 10D, the matching circuits 43 through 45, the LPF46, and the HPF 47 may be omitted. In the case illustrated in FIG. 10D,the circuit including the transmit filter 12 and the receive filter 14functions as a separating circuit.

As described in the first embodiment, the second embodiment, and thevariations thereof, the separating circuit preferably includes thediplexer 16 including an LPF connected between the terminal T1 and theterminal TL and an HPF connected between the terminal T1 and theterminal TH. This configuration enables to further separate signals ofthe low band and signals of the high band. As described in the secondvariation of the second embodiment, the separating circuit may notinclude a diplexer.

The first and second embodiments and the variations thereof describe acase where, as the bands used for wireless communication such as LTE,the low band includes at least a part of a band from 699 to 960 MHz, themiddle band includes at least a part of a band from 1710 to 2170 MHz,and the high band includes at least a part of a band from 2305 to 2690MHz, as an example. The low band, the middle band, and the high band maybe other than these frequencies.

A description has been given of a case where each of the low band, themiddle band, and the high band includes two or more bands each includinga transmit band and a receive band, as an example. At least one of thelow band, the middle band, and the high band may include two or morebands each including a transmit band and a receive band. Each of the lowband, the middle band, and the high band may include only one band.

In the second embodiment and the variations thereof, the switches 23 and24 may be replaced with multiplexers such as diplexers. This reduces thenumber of wiring lines for the power source and control signals used forthe switch. Accordingly, the size of the front end circuit can bereduced.

Third Embodiment

The third embodiment is an exemplary module including a front endcircuit or a part of the front end circuit. FIG. 11 is a circuit diagramof a middle band circuit in the third embodiment. As illustrated in FIG.11, a circuit of the third embodiment is the same as the middle bandcircuit 10M of the first variation of the second embodiment.

FIG. 12A and FIG. 12B illustrate a module in accordance with a thirdcomparative example. As illustrated in FIG. 12A and FIG. 12B, the moduleincludes a substrate 50, the transmit filters 12, and the receivefilters 14. The transmit filters 12 and the receive filters 14 aremounted on the substrate 50, or embedded in the substrate 50. Thesubstrate 50 is a wiring substrate formed by stacking, for example,resin layers. The transmit filter 12 and the receive filter 14 areinterconnected through a wiring line 52 formed in the substrate 50. B1Rxthrough B4Rx correspond to the receive filters 14 for LTE bands B1through B4, respectively, and B1Tx through B4Tx correspond to thetransmit filters 12 for LTE bands B1 through B4, respectively.

As illustrated in FIG. 1, the transmit band of LTE band B1 partiallyoverlap with the receive band of LTE band B2. As indicated by the dashedline arrow in FIG. 12A, a signal input from the transmit terminal forLTE band B1 is input to the switch 21 a. Since the isolation in theswitch 21 a is finite, a part of the transmission signal of LTE band B1leaks to the receive filter 14 for LTE band B2. When the receive filters14 for LTE bands B2 and B1 are adjacent to each other, the couplingbetween LTE bands B2 and B1 is large. Thus, the signal of the receivefilter 14 for LTE band B2 (a part of the transmission signal of LTE bandB1) is output as the reception signal of LTE band B1. This decreases thereceiving sensitivity of LTE band B1.

In the same manner, the transmit band of LTE band B2 partially overlapswith the receive band of LTE band B3. As indicated by the dashed linearrow in FIG. 12B, a signal input from the transmit terminal for LTEband B2 is input to the switch 21 a. A part of the transmission signalof LTE band B2 leaks to the receive filter 14 for LTE band B3. When thereceive filters 14 for LTE bands B3 and B2 are adjacent to each other,the signal of the receive filter 14 for LTE band B3 (a part of thetransmission signal of LTE band B2) is output as the reception signal ofLTE band B2. This decreases the receiving sensitivity of LTE band B2.

FIG. 13 is a schematic plan view illustrating a module in accordancewith the third embodiment. The transmit filters 12 and the receivefilters 14 for LTE bands B1 through B4 are mounted on the substrate 50,or embedded in the substrate 50. The multi-throw RF switch 21 a islocated outside the module. The receive filters 14 are located in theorder of LTE bands B1, B3, B4, and B2. Thus, the receive filters 14 forLTE bands B1 and B2 are not adjacent to each other, and the receivefilters 14 for LTE bands B2 and B3 are not adjacent to each other. Thisconfiguration can reduce the degradation in the receiving sensitivity ofLTE bands B1 and B2 described in FIG. 12A and FIG. 12B.

FIG. 14 is a schematic plan view illustrating a module in accordancewith a first variation of the third embodiment. As illustrated in FIG.14, the switch 21 a is mounted on or embedded in the substrate 50. Otherconfigurations are the same as those of the third embodiment, and thusthe description thereof is omitted.

FIG. 15 is a schematic plan view illustrating a module in accordancewith a second variation of the third embodiment. As illustrated in FIG.15, the switch 26 and the power amplifier 36 e are mounted on orembedded in the substrate 50. Other configurations are the same as thoseof the first variation of the third embodiment, and thus the descriptionthereof is omitted.

As illustrated in FIG. 14 and FIG. 15, at least one of the switches 21a, 26 and the power amplifier 36 e may be mounted on or embedded in thesubstrate 50 in addition to the transmit filters 12 and the receivefilters 14. Alternatively, other components may be mounted on orembedded in the substrate 50.

FIG. 16 is a circuit diagram of a middle band circuit in a thirdvariation of the third embodiment. As illustrated in FIG. 16, thetransmit filters 12 and the receive filters 14 for LTE bands B2 and B4are included in the quadplexer 15 c. The transmit filters 12 and thereceive filters 14 for LTE bands B1 and B3 are included in thequadplexer 15 d. The multi-throw RF switch 21 a is replaced with theSP3T switch 21. Other configurations are the same as those of the thirdembodiment, and thus the description thereof is omitted. The isolationbetween Throws in a switch such as a SP3T having a small number ofThrows is greater than that in a switch having a large number of Throws.Thus, the third variation of the third embodiment can further reduce theinterference between bands.

Even when the transmit filters 12 and the receive filters 14 form amultiplexer such as a quadplexer as described in the third variation ofthe third embodiment, the receive filters 14 for LTE bands B1 and B2 arepreferably not adjacent to each other, and the receive filters 14 forLTE bands B2 and B3 are preferably not adjacent to each other.

FIG. 17 is a schematic plan view illustrating a module in accordancewith the third variation of the third embodiment. As illustrated in FIG.17, the transmit filters 12 and the receive filters 14 for LTE bands B1and B3 are mounted on the substrate 50 as the quadplexer 15 d. Thetransmit filters 12 and the receive filters 14 for LTE bands B2 and B4are mounted on the substrate 50 as the quadplexer 15 c. Each of thequadplexers 15 c and 15 d is packaged. Other configurations are the sameas those of the second variation of the second embodiment, and thus thedescription thereof is omitted. Even when the transmit filters 12 andthe receive filters 14 are mounted on the substrate 50 as thequadplexers 15 c and 15 d, the receive filters 14 for LTE bands B1 andB2 are configured not to be adjacent to each other, and the receivefilters 14 for LTE bands B2 and B3 are configured not to be adjacent toeach other. This configuration enables to reduce the deterioration inthe isolation between LTE bands B2 and B3. The same applies to a casewhere the transmit filters 12 and the receive filters 14 are packaged ina unit of a duplexer or in a unit of a filter.

FIG. 18 is a circuit diagram of a low band circuit in a fourth variationof the third embodiment. As illustrated in FIG. 18, the circuit of thefourth variation of the third embodiment includes duplexers for LTEbands B8, B20, B12, and B26 in the low band circuit 10L of the firstvariation of the second embodiment. The multi-throw RF switch 20 ahaving seven throws of the first variation of the second embodiment isreplaced with the multi-throw RF switch 20 a having five throws. Otherconfigurations are the same as those of the first variation of thesecond embodiment, and thus the description thereof is omitted.

FIG. 19 is a schematic plan view illustrating a module in accordancewith a fourth comparative example. As illustrated in FIG. 19, the moduleincludes the substrate 50, the transmit filters 12, and the receivefilters 14. The transmit filters 12 and the receive filters 14 aremounted on or embedded in the substrate 50. The substrate 50 is a wiringsubstrate formed by stacking, for example, resin layers. The transmitfilter 12 and the receive filter 14 are interconnected through thewiring line 52 formed in the substrate 50. The transmit filters 12 andthe receive filters 14 support LTE bands B8, B12, B20, and B26. Otherconfigurations are the same as those of the third comparative example,and thus the description thereof is omitted.

As illustrated in FIG. 1, the transmit band of LTE band B26 partiallyoverlaps with the receive band of LTE band B20. The transmit band of LTEband B8 partially overlaps with the receive band of LTE band B26. Thus,as indicated by the dashed line arrow in FIG. 19, a signal input fromthe transmit terminal for LTE band B26 is input to the switch 20a. Apart of the transmission signal of LTE band B26 leaks to the receivefilter 14 for LTE band B20. When the receive filters 14 for LTE bandsB26 and B20 are adjacent to each other, the signal of the receive filter14 for LTE band B20 (a part of the transmission signal of LTE band B26)is output as the reception signal of LTE band B26. This decreases thereceiving sensitivity of LTE band B26. In the same manner, when thereceive filters 14 for LTE bands B8 and B26 are adjacent to each other,a part of the transmission signal of LTE band B8 is output as thereception signal of LTE band B8. This decreases the receivingsensitivity of LTE band B8.

FIG. 20 is a schematic plan view illustrating a module in accordancewith the fourth variation of the third embodiment. As illustrated inFIG. 20, the transmit filters 12 and the receive filters 14 for LTEbands B8, B12, B20, and B26 are mounted on or embedded in the substrate50. The multi-throw RF switch 20 a is located outside the module. Thereceive filters 14 are located in the order of LTE bands B8, B20, B12,and B26. Thus, the receive filters 14 for LTE bands B8 and B26 are notadjacent to each other, and the receive filters 14 for LTE bands B20 andB26 are not adjacent to each other. This configuration can reduce thedegradation in the receiving sensitivity of LTE bands B26 and B8described in FIG. 19.

At least one of a switch, an amplifier, and other components may bemounted on or embedded in the substrate 50 in addition to the transmitfilters 12 and the receive filters 14. Additionally, the transmitfilters 12 and the receive filters 14 may form a multiplexer.

In the third embodiment and the variations thereof, the transmissionband of a first band (e.g., LTE band B1) overlaps with at least a partof the receive band of a second band (e.g., LTE band B2), and thereceive band of a third band (e.g., LTE band B4) does not overlap withthe transmit band of the first band or the transmit band of the secondband. In this case, the receive filter for the third band is locatedbetween the receive filter for the first band and the receive filter forthe second band. This configuration prevents the transmission signal ofthe first band from passing through the receive filter for the secondband and leaking to the receive filter for the first band. Therefore,the degradation in the receiving sensitivity of the first band can bereduced.

In a module including the transmit filters 12 and the receive filters 14for LTE bands B1 through B4, the receive filters 14 are arranged in theorder of LTE bands B1, B3, B4, and B2. This arrangement can reduce thedegradation in the receiving sensitivity of LTE bands B1 and B2.Moreover, in a module including the transmit filters 12 and the receivefilters 14 for LTE bands B8, B12, B20, and B26, the receive filters 14are arranged in the order of LTE bands B8, B20, B12, and B26. Thisarrangement can reduce the degradation in the receiving sensitivity ofLTE bands B8 and B26.

As illustrated in FIG. 1, the transmit band of LTE band B25 overlapswith the transmit band of LTE band B2, and the receive band of LTE bandB25 overlaps with the receive band of LTE band B2. Thus, instead of thereceive filter 14 and the transmit filter 12 for LTE band B2, thereceive filter 14 and the transmit filter 12 for LTE band B25 may beused in the third embodiment and the variations thereof. The transmitband of LTE band B5 overlaps with the transmit band of LTE band B26, andthe receive band of LTE band B5 overlaps with the receive band of LTEband B26. Thus, instead of the receive filter 14 and the transmit filter12 for LTE band B26, the receive filter 14 and the transmit filter 12for LTE band B5 may be used in the fourth variation of the thirdembodiment. The transmit band of LTE band B17 overlaps with the transmitband of LTE band B12, and the receive band of LTE band B17 overlaps withthe receive band of LTE band B12. Thus, instead of the receive filter 14and the transmit filter 12 for LTE band B12, the receive filter 14 andthe transmit filter 12 for LTE band B17 may be used in the fourthvariation of the third embodiment.

As with in the third embodiment and the variations thereof, the transmitfilter 12 and the receive filter 14 for the same band may be arrangednext to each other, or the transmit filters 12 may be arranged in theorder different from the arrangement order of the receive filters 14.

The third embodiment and the variations thereof can be applied to thefirst and second embodiments and the variations thereof.

Fourth Embodiment

The fourth embodiment performs carrier aggregation. FIG. 21 is aschematic plan view illustrating another module in accordance with thethird variation of the third embodiment. As illustrated in FIG. 21, thequadplexers 15 c and 15 d are mounted on the substrate 50. The receivefilters 14 for LTE bands B3 and B4 are located next to each other. TheSP3T switch 21, the SP4T switch 26, and the power amplifier 36 e are notmounted on the substrate 50. Other configurations are the same as thoseof the third variation of the third embodiment illustrated in FIG. 16,and thus the description thereof is omitted.

During carrier aggregation, signals of LTE bands B2 and B4 aresimultaneously received. At this time, leakage of the signal from thetransmit terminal for LTE band B2 to the receive terminals for LTE bandsB2 and B4, and leakage of the signal from the transmit terminal for LTEband B4 to the receive terminals for LTE bands B4 and B2 become aproblem.

As indicated by the dashed line arrow in FIG. 21, a transmission signalinput from the transmit terminal for LTE band B2 reaches the switch 21.Since the transmit band of LTE band B2 partially overlaps with thereceive band of LTE band B3, a part of the transmission signal of LTEband B2 leaks to the receive filter 14 for LTE band B3 in the switch 21.When the receive filters 14 for LTE bands B3 and B4 are adjacent to eachother, the coupling between LTE bands B3 and B4 is large. Thus, thesignal of the receive filter 14 for LTE band B3 (a part of thetransmission signal of LTE band B2) is output as the reception signal ofLTE band B4. This decreases the receiving sensitivity of LTE band B4.

FIG. 22 is a schematic plan view illustrating a module in accordancewith the fourth embodiment. As illustrated in FIG. 22, the receivefilters 14 are arranged so that the receive filters 14 for LTE bands B1and B4 are adjacent to each other. Other configurations are the same asthose of FIG. 21, and thus the description thereof is omitted. Asindicated by the dashed line arrow in FIG. 22, even when a part of thetransmission signal of LTE band B2 leaks to the receive filter 14 forLTE band B3, the receive filter 14 for LTE band B3 and the receivefilters 14 for LTE bands B2 and B4 are not adjacent to each other. Thus,a part of the transmission signal of LTE band B2 can be prevented fromleaking to the receive terminals for LTE bands B2 and B4. Accordingly,the degradation in the receiving sensitivity of LTE bands B2 and B4 canbe reduced.

Signals of LTE bands B1 and B3 are simultaneously received duringcarrier aggregation. Thus, it is preferable to prevent leakage of thesignal from the transmit terminal for LTE band B1 to the receiveterminals for LTE bands B1 and B3 and leakage of the signal from thetransmit terminal for LTE band B3 to the receive terminals for LTE bandsB3 and B1. The transmit band of LTE band B1 partially overlaps with thereceive band of LTE band B2. Thus, as indicated by the long intervaldashed line arrow, a part of the transmission signal of LTE band B1leaks to the receive filter 14 for LTE band B2 through the switch 21.However, the receive filter 14 for LTE band B2 and the receive filters14 for LTE bands B3 and B1 are not adjacent to each other. Thus, a partof the transmission signal of LTE band B1 can be prevented from leakingto the receive terminals for LTE bands B1 and B3. Accordingly, thedegradation in the receiving sensitivity of LTE bands B1 and B3 can bereduced.

FIG. 23 is a schematic plan view illustrating a module in accordancewith a first variation of the fourth embodiment. As illustrated in FIG.23, the switch 21 is mounted on or embedded in the substrate 50. Otherconfigurations are the same as those of the fourth embodiment, and thusthe description thereof is omitted.

FIG. 24 is a schematic plan view illustrating a module in accordancewith a second variation of the fourth embodiment. As illustrated in FIG.24, the switch 26 and the power amplifier 36 e are mounted on orembedded in the substrate 50. Other configurations are the same as thoseof the first variation of the fourth embodiment, and thus thedescription thereof is omitted.

As illustrated in FIG. 23 and FIG. 24, at least one of the switches 21,26, and the power amplifier 36 e may be mounted on or embedded in thesubstrate 50 in addition to the transmit filters 12 and the receivefilters 14. Alternatively, other components may be mounted on orembedded in the substrate 50.

FIG. 25 is a schematic plan view illustrating another module inaccordance with the fourth variation of the third embodiment. Asillustrated in FIG. 25, the quadplexers 15 h and 15 i are mounted on thesubstrate 50. The transmit filters 12 and the receive filters 14 for LTEbands B8 and B20 are included in the quadplexer 15 i. The transmitfilters 12 and the receive filters 14 for LTE bands B12 and B26 areincluded in the quadplexer 15 h. Other configurations are the same asthose of FIG. 20, and thus the description thereof is omitted.

Signals of LTE bands B12 and B26 are simultaneously received duringcarrier aggregation. Thus, it is preferable to prevent leakage of thesignal from the transmit terminal for LTE band B12 to the receiveterminals for LTE bands B12 and B26 and leakage of the signal from thetransmit terminal for LTE band B26 to the receive terminals for LTEbands B12 and B26. The transmit band of LTE band B26 partially overlapswith the receive band of LTE band B20. Thus, as indicated by the dashedline arrow, a part of the transmission signal of LTE band B26 leaks tothe receive filter 14 for LTE band B20 through the switch 20. Thereceive filters 14 for LTE bands B12 and B20 are adjacent to each other.Thus, a part of the transmission signal of LTE band B26 leaks to thereceive terminal for LTE band B12. Accordingly, the receivingsensitivity of LTE band B12 decreases.

FIG. 26 is a schematic plan view illustrating a module in accordancewith a third variation of the fourth embodiment. As illustrated in FIG.26, the receive filters 14 are arranged so that the receive filters 14for LTE bands B8 and B12 are adjacent to each other. Otherconfigurations are the same as those of FIG. 25, and thus thedescription thereof is omitted. As indicated by the dashed line arrow inFIG. 26, even when a part of the transmission signal of LTE band B26leaks to the receive filter 14 for LTE band B20, the receive filter 14for LTE band B20 and the receive filters 14 for LTE bands B12 and B26are not adjacent to each other. Thus, a part of the transmission signalof LTE band B26 can be prevented from leaking to the receive terminalsfor LTE bands B12 and B26. Accordingly, the degradation in the receivingsensitivity of LTE bands B12 and B26 can be reduced.

In the fourth embodiment and the variations thereof, the receptionsignal of a first band (e.g., LTE band B1) and the reception signal of asecond band (e.g., LTE band B3) are simultaneously received. The receiveband of a third band (e.g., LTE band B2) overlaps with at least a partof the transmit band of the first band. The receive band of a fourthband (e.g., LTE band B4) does not overlap with the transmit band of thefirst band. In this case, the receive filter for the fourth band islocated between the receive filters for the first band and the secondband and the receive filter for the third band. This configuration canprevent the transmission signal of the first band from passing throughthe receive filter for the third band and leaking to the receive filtersfor the first band and the second band. Accordingly, the degradation inthe receiving sensitivity of the first band and the second band can bereduced.

In addition, it becomes a problem that a part of the transmission signalof the second band leaks to the receive filter 14 for the fourth band,and then leaks from the receive filter 14 for the fourth band to thereceive filter 14 for the first or second band. Thus, it is preferablethat the receive band of the fourth band does not overlap with thetransmit band of the second band.

To prevent leakage of the signal between different bands, it ispreferable to arrange the receive filters 14 in the order of LTE bandsB3, B1, B4, and B2 in a module including the transmit filters 12 and thereceive filters 14 for LTE bands B1 through B4. Moreover, it ispreferable to arrange the receive filters 14 in the order of LTE bandsB20, B8, B12, and B26 in a module including the transmit filters 12 andthe receive filters 14 for LTE bands B8, B12, B20, and B26.

As illustrated in FIG. 1, the transmit band of LTE band B25 overlapswith the transmit band of LTE band B2, and the receive band of LTE bandB25 overlaps with the receive band of LTE band B2. Thus, instead of thereceive filter 14 and the transmit filter 12 for LTE band B2, thereceive filter 14 and the transmit filter 12 for LTE band B25 may beused in the fourth embodiment and the variations thereof. The transmitband of LTE band B5 overlaps with the transmit band of LTE band B26, andthe receive band of LTE band B5 overlaps with the receive band of LTEband B26. Thus, instead of the receive filter 14 and the transmit filter12 for LTE band B26, the receive filter 14 and the transmit filter 12for LTE band B5 may be used in the fourth embodiment and the variationsthereof. The transmit band of LTE band B17 overlaps with the transmitband of LTE band B12, and the receive band of LTE band B17 overlaps withthe receive band of LTE band B12. Thus, instead of the receive filter 14and the transmit filter 12 for LTE band B12, the receive filter 14 andthe transmit filter 12 for LTE band B17 may be used in the fourthembodiment and the variations thereof.

In the fourth embodiment and the variations thereof, the transmit filter12 and the receive filter 14 are included in a quadplexer, but thetransmit filter 12 and the receive filter 14 may be individually mountedon the substrate 50. Additionally, a switch, a power amplifier, and thelike may be mounted on the substrate 50.

Fifth Embodiment

FIG. 27A is a block diagram around an antenna of a communication devicein accordance with the fifth embodiment, and FIG. 27B is a perspectiveview of the antenna. As illustrated in FIG. 27A, the terminal T1 iscoupled to the low band antenna 40L and the high band antenna 40H. Theterminal T2 is coupled to the middle band antenna 40M.

As illustrated in FIG. 27B, a metal film 56 is formed on a dielectricsubstance 54. The metal film includes signal terminals 50LH and 50M,ground terminals 52LH and 52M, the low band antenna 40L, the high bandantenna 40H, and the middle band antenna 40M. The antennas 40L, 40H, and40M are antenna radiators. The low band antenna 40L is coupled to thehigh band antenna 40H on the dielectric substance 54. The signalterminal 50LH and the ground terminal 52LH are coupled to a region wherethe low band antenna 40L is coupled to the high band antenna 40H. Themiddle band antenna 40M electrically separates from the low band antenna40L and the high band antenna 40H. The signal terminal 50M and theground terminal 52M are coupled to the middle band antenna 40M. Otherconfigurations are the same as those of the first embodiment, and thusthe description thereof is omitted.

In the fifth embodiment, the low band antenna 40L and the high bandantenna 40H share the signal terminal 50LH and the ground terminal 52LH.This configuration enables to reduce the size and the cost.

FIG. 28A is a block diagram around an antenna of a communication devicein accordance with a first variation of the fifth embodiment, and FIG.28B is a perspective view of the antenna. As illustrated in FIG. 28A andFIG. 28B, the low band antenna 40L is located between the high bandantenna 40H and the middle band antenna 40M. Other configurations arethe same as those of the fifth embodiment, and thus the descriptionthereof is omitted.

When the high band antenna 40H is located between the low band antenna40L and the middle band antenna 40M like in the fifth embodiment, theisolation between the high band antenna 40H and the middle band antenna40M deteriorates.

In the first variation of the fifth embodiment, the low band antenna 40Lis located between the high band antenna 40H and the middle band antenna40M. This configuration enables to improve the isolation between thehigh band antenna 40H and the middle band antenna 40M. The low bandantenna 40L is adjacent to the middle band antenna 40M. However, asillustrated in FIG. 1, the frequency interval between the low band andthe middle band is wider than the frequency interval between the middleband and the high band. Thus, the isolation between the low band antenna40L and the middle band antenna 40M little deteriorates. Additionally,the signal terminal can be shared by the high band and the low band, andthus the cost and the size can be reduced.

The fifth embodiment and the variation thereof can be applied to thefirst through fourth embodiments and the variations thereof.

Sixth Embodiment

A sixth embodiment is an exemplary module including common terminals aswith in the third embodiment, the fourth embodiment, and the variationsthereof. FIG. 29A is a plan view of the module in accordance with thefourth embodiment, and FIG. 29B is a plan view of a module in accordancewith the sixth embodiment. As illustrated in FIG. 29A, in the moduleillustrated in FIG. 22 of the fourth embodiment, the quadplexer 15 dincludes receive filters 14 a and transmit filters 12 a (first filters),and the quadplexer 15 c includes receive filters 14 b and transmitfilters 12 b (second filters). Each of the receive filters 14 a isconnected between a common terminal Ant1 (a first common terminal) and areceive terminal Rx (a first terminal). Each of the transmit filters 12a is connected between the common terminal Ant1 and a transmit terminalTx (a second terminal). Each of the receive filters 14 b is connectedbetween a common terminal Ant2 (a second common terminal) and thereceive terminal Rx. Each of the transmit filters 12 b is connectedbetween the common terminal Ant2 and the transmit terminal Tx.

A wiring line L1 commonly connects the receive filters 14 a and thetransmit filters 12 a to the common terminal Ant1. A wiring line L2commonly connects the receive filters 14 b and the transmit filters 12 bto the common terminal Ant2. The wiring lines L1 and L2 are formed inthe substrate 50.

The wiring line L1 includes a wiring line L11 that interconnects thereceive filter 14a and the transmit filter 12 a for LTE band B3, and awiring line L12 that interconnects the receive filter 14 a and thetransmit filter 12 a for LTE band B1. Thus, the wiring line L2intersects with two wiring lines L11 and L12 of the wiring line L1 inintersect regions 78. A high-frequency signal is reflected in theintersect region 78 of the wiring lines L1 and L2. This deteriorateshigh-frequency characteristics.

As illustrated in FIG. 29B, in the sixth embodiment, the receive filters14 a and the transmit filters 12 a are interconnected by a single wiringline L13 of the wiring line L1 in the quadplexer 15 d. Otherconfigurations are the same as those of the fourth embodimentillustrated in FIG. 29A, and thus the description thereof is omitted.Thus, the number of the intersect regions 78 at which the wiring linesL1 and L2 intersect is one. This reduces the deterioration ofhigh-frequency characteristics.

A description will next be given of an example of the arrangement ofwiring lines in the sixth embodiment. FIG. 30 is a cross-sectional viewof the module of the sixth embodiment. As illustrated in FIG. 30, thesubstrate 50 includes stacked insulating layers 60 through 62. Theinsulating layers 60 through 62 are, for example, resin layers. Metallayers 63 are formed on the upper surfaces of the insulating layers 60through 62 and the lower surface of the insulating layer 62. The metallayer 63 is, for example, a copper layer or a gold layer. Wiring lines64, pads 66, and foot pads 67 are formed of the metal layers 63. Vias 65piercing through the insulating layers 60 through 62 are formed. A metalsuch as copper is embedded in the via 65. The transmit filter 12 and thereceive filter 14 are mounted on the pads 66 through solder 68. Thetransmit filter 12 and the receive filter 14 are integrated in a chip ora package in which filters are formed.

FIG. 31A through FIG. 32B are plan views of the insulating layers in thesixth embodiment. FIG. 31A through FIG. 32A are plan views of the uppersurfaces of the insulating layers 60 through 62, respectively, and FIG.32B is a transparent view of the lower surface of the insulating layer62 viewed from above. In FIG. 31A, the filters 12 a, 12 b, 14 a, and 14b are illustrated by dashed lines.

As illustrated in FIG. 31A, the metal layer 63 is formed on the uppersurface of the insulating layer 60, and the vias 65 piercing through theinsulating layer 60 are formed. The receive filters 14 a and thetransmit filters 12 a in the quadplexer 15 d and the receive filters 14b and the transmit filters 12 b in the quadplexer 15 c are mounted onthe insulating layer 60. The metal layer 63 includes the wiring lines64, and the pads 66. The wiring lines 64 include the wiring lines L1,L2, and a ground pattern Gnd. The pads 66 include receive pads Prx,transmit pads Ptx, and common pads Pant.

Each of the receive filters 14 a and 14 b is coupled to thecorresponding receive pad Prx and to the corresponding common pad Pantby solder 68. Each of the transmit filters 12 a and 12 b is coupled tothe corresponding transmit pad Ptx and the corresponding common pad Pantby solder 68. The ground of each of the filters 12 a, 12 b, 14 a, and 14b is coupled to a region 69 in the ground pattern Gnd by solder 68. Thewiring line L1 commonly connects the common pads Pant to which thereceive filters 14 a and the transmit filters 12 a are connected. Thewiring line L2 commonly connects the common pads Pant to which thereceive filters 14 b and the transmit filters 12 b are connected. Thewiring line L2 is not formed in the intersect region 78 where the wiringlines L1 and L2 intersect. The ground pattern Gnd is formed to surroundthe wiring lines 64 and the pads 66. The vias 65 each piercing throughthe insulating layer 60 and connecting to the wiring line 64 are formed.

As illustrated in FIG. 31B, the metal layer 63 is formed on the uppersurface of the insulating layer 61. The metal layer includes the wiringlines 64. The wiring lines 64 include a part of the wiring line L2 inthe intersect region 78 and the ground pattern Gnd. The vias 65 eachpiercing through the insulating layer 61 and connecting to the wiringline 64 are formed. As illustrated in FIG. 32A, the metal layer 63 isformed on the upper surface of the insulating layer 62. The vias 65 eachpiercing through the insulating layer 62 and connecting to the wiringline 64 are formed.

As illustrated in FIG. 32B, the metal layer 63 is formed on the lowersurface of the insulating layer 62. The metal layer 63 includes the footpads 67. The foot pads 67 include receive foot pads Frx, transmit footpads Ftx, common foot pads Fant1, Fant2, and a ground foot pad Fgnd. Thereceive foot pads Frx, the transmit foot pads Ftx, and the common footpads Fant1 and Fant2 correspond to the receive terminals Rx, thetransmit terminals Tx, and the common terminals Ant1 and Ant2 in FIG.29B, respectively. The vias 65 each piercing through the insulatinglayer 62 and connecting to the foot pad 67 are formed.

As illustrated in FIG. 31A through FIG. 32B, the wiring line L1 iselectrically connected to the common foot pad Fant1 through the wiringlines 64 and the vias 65 of the insulating layers 60 through 62. Thewiring line L2 is electrically connected to the common foot pad Fant2through the wiring lines 64 and the vias 65 of the insulating layers 60through 62. The receive pads Prx are electrically connected to thereceive foot pads Frx through the wiring lines 64 and the vias 65, andthe transmit pads Ptx are electrically coupled to the transmit foot padsFtx through the wiring lines 64 and the vias 65. The ground patterns Gndand the ground foot pad Fgnd formed on the upper surfaces of theinsulating layers 60 through 62 are electrically interconnected throughthe vias 65, but FIG. 31A through FIG. 32B do not illustrate the groundvias 65.

FIG. 33 is a plan view of the insulating layer 60 in the fourthembodiment. As illustrated in FIG. 33, in the fourth embodiment, thewiring lines L1 and L2 intersect in two intersect regions 78. Otherconfigurations are the same as those of FIG. 30 through FIG. 32B, andthus the description thereof is omitted.

In the sixth embodiment, as illustrated in FIG. 29B through FIG. 32B,the receive filter 14 a and the transmit filter 12 a have differentpassbands, and the receive filter 14 b and the transmit filter 12 b havedifferent passbands. That is to say, the passband of the receive filter14 a does not overlap with the passband of the transmit filter 12 a, andthe passband of the receive filter 14 b does not overlap with thepassband of the transmit filter 12 b. The common terminals Ant1 and Ant2are located at the same side as the receive filter 14 a and the transmitfilter 12 a. The receive filter 14 b and the transmit filter 12 b areopposite the common terminals Ant1 and Ant2 across the receive filter 14a and the transmit filter 12 a. In such an arrangement, the wiring lineL2 intersects the wiring line L1 in a single region. This configurationimproves high-frequency characteristics compared to a case where thewiring line L2 intersects the wiring line L1 in two or more regions aswith in the fourth embodiment of FIG. 29A through FIG. 33.

The sixth embodiment describes a case where each of the wiring line L1and the wiring line L2 are coupled to four filters. The wiring line L1is required to connect at least three first filters to the commonterminal Ant1. The wiring line L2 is required to connect at least onesecond filter to the common terminal Ant2. When the number of thereceive filters 14 a and the number of the transmit filters 12 a are atleast three, the number of the intersect regions 78 where the wiringline L1 intersects the wiring line L2 is two or more, and thushigh-frequency characteristics may deteriorate. The sixth embodimentconfigures the number of the intersect regions 78 to be one, therebyreducing the deterioration of high-frequency characteristics.

Additionally, the receive filter 14 a and the transmit filter 12 a arelocated at both sides of the wiring line L1. In this case, the number ofthe intersect regions 78 easily becomes two or more, and high-frequencycharacteristics may deteriorate. The sixth embodiment configures thenumber of the intersect regions 78 to be one, thereby reducing thedeterioration of high-frequency characteristics. Moreover, when thereceive filter 14 a and the transmit filter 12 a are located at bothsides of the wiring line L1, the ground pattern Gnd and the ground viaconnected to the receive filter 14 a can be separated from the groundpattern Gnd and the ground via connected to the transmit filter 12 a.This decreases the impedance shared by the receive filter 14 a and thetransmit filter 12 a, thereby reducing the interference between thereception signal and the transmission signal.

Furthermore, the wiring line L2 connects at least three second filtersto the common terminal Ant2. In this case, even when the second filteris located closer to the common terminals Ant1 and Ant2 than the firstfilter, the number of the intersect regions 78 easily becomes two ormore, and high-frequency characteristics may deteriorate. The sixthembodiment configures the number of the intersect regions 78 to be one,thereby reducing the deterioration of high-frequency characteristics.

In the sixth embodiment, the first filter includes the receive filter 14a and the transmit filter 12 a, and the second filter includes thereceive filter 14 b and the transmit filter 12 b. However, the firstfilter may include only one of the receive filter and the transmitfilter, and the second filter may include only the other of the receivefilter and the transmit filter.

As described in the sixth embodiment, the first filter includes thetransmit filter 12 a (a first transmit filter) and the receive filter 14a (a first receive filter) for LTE band B3 (a first band), and thetransmit filter 12 a (a second transmit filter) and the receive filter14 a (a second receive filter) for LTE band B1 (a second band). Thesecond filter includes the transmit filter 12 b (a third transmitfilter) and the receive filter 14 b (a third receive filter) for LTEband B4 (a third band), and the transmit filter 12 b (a fourth transmitfilter) and the receive filter 14 b (a fourth receive filter) for LTEband B2 (a fourth band). As described above, when the quadplexers 15 dand 15 c for different bands are mounted on the substrate 50, the wiringbecomes complicated, and high-frequency characteristics easilydeteriorate. The deterioration of high-frequency characteristics can bereduced by configuring the number of the intersect regions 78 to be one.LTE bands B3, B1, B4, and B2 are used as an example, but the abovediscussion is applicable to other bands.

In the intersect region 78, the wiring line L1 and the wiring line L2are formed on the surfaces of the different insulating layers 60 and 61among the insulating layers 60 through 62. Thus, the wiring line L1 caneasily intersect with the wiring line L2. However, the distance betweenthe wiring lines L1 and L2 in the intersect region 78 decreases, andhigh-frequency signals easily interfere. Therefore, the deterioration ofhigh-frequency characteristics can be reduce by configuring the numberof the intersect regions 78 to be one.

FIG. 34A and FIG. 34B are plan views of the insulating layers in a firstvariation of the sixth embodiment. FIG. 34A and FIG. 34B are plan viewsof the insulating layers 61 and 62, respectively. The upper surface ofthe insulating layer 60 and the lower surface of the insulating layer 62are the same as those in the sixth embodiment illustrated in FIG. 31Aand FIG. 32B.

As illustrated in FIG. 34A, the wiring line L2 is not formed in theintersect region 78 of the insulating layer 61. The ground pattern Gndis formed in the intersect region 78. As illustrated in FIG. 34B, thewiring line L2 including the intersect region 78 is formed. Otherconfigurations are the same as those of the sixth embodiment, and thusthe description thereof is omitted.

In the first variation of the sixth embodiment, the ground pattern Gndis located between the wiring line L1 and the wiring line L2 in theintersect region 78 where the wiring line L1 intersects the wiring lingL2. This configuration reduces the interference of high-frequencysignals in the intersect region 78, and improves high-frequencycharacteristics. In the intersect region 78, two or more insulatinglayers may be located between the wiring lines L1 and L2. In theintersect region 78, two or more ground patterns Gnd may be locatedbetween the wiring lines L1 and L2.

The module of the sixth embodiment and the variation thereof can beapplied to the first through fifth embodiments and the variationsthereof.

Although the embodiments of the present invention have been described indetail, it is to be understood that the various change, substitutions,and alterations could be made hereto without departing from the spiritand scope of the invention.

What is claimed is:
 1. A front end circuit comprising: a first antennaterminal that is coupled to a first antenna, from which transmissionsignals of a low band and a high band are output, and to which receptionsignals of the low band and the high band are input, frequency of thehigh band being higher than frequency of the low band; a second antennaterminal that is coupled to a second antenna different from the firstantenna, from which a transmission signal of a middle band is output,and to which a reception signal of the middle band is input, frequencyof the middle band being higher than the frequency of the low band andbeing lower than the frequency of the high band; a low band terminal towhich the transmission signal of the low band is input, and from whichthe reception signal of the low band is output; a middle band terminalto which the transmission signal of the middle band is input, and fromwhich the reception signal of the middle band is output; a high bandterminal to which the transmission signal of the high band is input, andfrom which the reception signal of the high band is output; and aseparating circuit that passes the transmission signal and the receptionsignal of the low band between the first antenna terminal and the lowband terminal, suppresses the transmission signal and the receptionsignal of the middle band and the transmission signal and the receptionsignal of the high band between the first antenna terminal and the lowband terminal, passes the transmission signal and the reception signalof the high band between the first antenna terminal and the high bandterminal, and suppresses the transmission signal and the receptionsignal of the low band and the transmission signal and the receptionsignal of the middle band between the first antenna terminal and thehigh band terminal.
 2. The front end circuit according to claim 1,wherein the separating circuit includes a low-pass filter connectedbetween the first antenna terminal and the low band terminal, and ahigh-pass filter connected between the first antenna terminal and thehigh band terminal.
 3. The front end circuit according to claim 1,wherein the low band includes at least a part of a band from 699 to 960MHz, the middle band includes at least a part of a band from 1710 to2170 MHz, and the high band includes a part of a band from 2305 to 2690MHz.
 4. The front end circuit according to claim 1, wherein at least oneof the low band, the middle band, and the high band includes two or morebands each including a transmit band and a receive band.
 5. The frontend circuit according to claim 1, wherein each of the low band, themiddle band, and the high band includes two or more band each includinga transmit band and a receive band.
 6. The front end circuit accordingto claim 4, further comprising: transmit bandpass filters that passtransmission signals of bands; and receive bandpass filters that passreception signals of bands.
 7. The front end circuit according to claim6, wherein the bands include a first band, a second band, and a thirdband, a transmit band of the first band overlaps with at least a part ofa receive band of the second band, a receive band of the third band doesnot overlap with the transmit band of the first band or a transmit bandof the second band, and a receive filter for the third band is locatedbetween a receive filter for the first band and a receive filter for thesecond band.
 8. The front end circuit according to claim 6, wherein thebands include a first band, a second band, a third band, and a fourthband, a reception signal of the first band and a reception signal of thesecond band are simultaneously received, a receive band of the thirdband overlaps with at least a part of a transmit band of the first band,a receive band of the fourth band does not overlap with the transmitband of the first band or a transmit band of the second band, and areceive filter for the fourth band is located between a receive filterfor the second band and a receive filter for the third band.
 9. Thefront end circuit according to claim 1, wherein reception signals of atleast two bands of the low band, the middle band, and the high band aresimultaneously received, and/or transmission signals of the at least twobands are simultaneously transmitted.
 10. A module comprising: a frontend circuit including: a first antenna terminal that is coupled to afirst antenna, from which transmission signals of a low band and a highband are output, and to which reception signals of the low band and thehigh band are input, frequency of the high band being higher thanfrequency of the low band; a second antenna terminal that is coupled toa second antenna different from the first antenna, from which atransmission signal of a middle band is output, and to which a receptionsignal of the middle band is input, frequency of the middle band beinghigher than the frequency of the low band and being lower than thefrequency of the high band; a low band terminal to which thetransmission signal of the low band is input, and from which thereception signal of the low band is output; a middle band terminal towhich the transmission signal of the middle band is input, and fromwhich the reception signal of the middle band is output; a high bandterminal to which the transmission signal of the high band is input, andfrom which the reception signal of the high band is output; and aseparating circuit that passes the transmission signal and the receptionsignal of the low band between the first antenna terminal and the lowband terminal, suppresses the transmission signal and the receptionsignal of the middle band and the transmission signal and the receptionsignal of the high band between the first antenna terminal and the lowband terminal, passes the transmission signal and the reception signalof the high band between the first antenna terminal and the high bandterminal, and suppresses the transmission signal and the receptionsignal of the low band and the transmission signal and the receptionsignal of the middle band between the first antenna terminal and thehigh band terminal.
 11. A communication device comprising: a front endcircuit including: a first antenna terminal that is coupled to a firstantenna, from which transmission signals of a low band and a high bandare output, and to which reception signals of the low band and the highband are input, frequency of the high band being higher than frequencyof the low band; a second antenna terminal that is coupled to a secondantenna different from the first antenna, from which a transmissionsignal of a middle band is output, and to which a reception signal ofthe middle band is input, frequency of the middle band being higher thanthe frequency of the low band and being lower than the frequency of thehigh band; a low band terminal to which the transmission signal of thelow band is input, and from which the reception signal of the low bandis output; a middle band terminal to which the transmission signal ofthe middle band is input, and from which the reception signal of themiddle band is output; a high band terminal to which the transmissionsignal of the high band is input, and from which the reception signal ofthe high band is output; and a separating circuit that passes thetransmission signal and the reception signal of the low band between thefirst antenna terminal and the low band terminal, suppresses thetransmission signal and the reception signal of the middle band and thetransmission signal and the reception signal of the high band betweenthe first antenna terminal and the low band terminal, passes thetransmission signal and the reception signal of the high band betweenthe first antenna terminal and the high band terminal, and suppressesthe transmission signal and the reception signal of the low band and thetransmission signal and the reception signal of the middle band betweenthe first antenna terminal and the high band terminal.
 12. Thecommunication device according to claim 11, further comprising: a lowband antenna and a high band antenna that are coupled to the firstantenna terminal; and a middle band antenna that is coupled to thesecond antenna terminal, wherein the low band antenna is located betweenthe high band antenna and the middle band antenna.
 13. A modulecomprising: a first transmit filter that passes a transmission signal ofa first band; a first receive filter that passes a reception signal ofthe first band; a second transmit filter that passes a transmissionsignal of a second band; a second receive filter that passes a receptionsignal of the second band; a third transmit filter that passes atransmission signal of a third band; and a third receive filter thatpasses a reception signal of the third band, wherein a transmit band ofthe first band overlaps with at least a part of a receive band of thesecond band, a receive band of the third band does not overlap with thetransmit band of the first band or a transmit band of the second band,and the third receive filter is located between the first receive filterand the second receive filter.
 14. The module according to claim 13,wherein an output of the first transmit filter and an input of the firstreceive filter are commonly coupled to a first common terminal, and anoutput of the second transmit filter and an input of the second receivefilter are commonly coupled to a second common terminal.
 15. The moduleaccording to claim 14, further comprising: a switch that selects andconnects one of the first common terminal and the second common terminalto a third common terminal.
 16. A module comprising: a first transmitfilter that passes a transmission signal of a first band; a firstreceive filter that passes a reception signal of the first band; asecond transmit filter that passes a transmission signal of a secondband; a second receive filter that passes a reception signal of thesecond band; a third transmit filter that passes a transmission signalof a third band; a third receive filter that passes a reception signalof the third band; a fourth transmit filter that passes a transmissionsignal of a fourth band; and a fourth receive filter that passes areception signal of the fourth band, wherein the reception signal of thefirst band and the reception signal of the second band aresimultaneously received, a receive band of the third band overlaps withat least a part of a transmit band of the first band; a receive band ofthe fourth band does not overlap with the transmit band of the firstband or a transmit band of the second band, and the fourth receivefilter is located between the second receive filter and the thirdreceive filter.
 17. The module according to claim 16, wherein the firstband is LTE band 1, the second band is LTE band 3, and the third band isLTE band 2 or LTE band 25, the first band is LTE band 2 or LTE band 25,the second band is LTE band 4, and the third band is LTE band 3, thefirst band is LTE band 26, the second band is LTE band 12 or LTE band17, and the third band is LTE band 20, or the first band is LTE band 8,the second band is LTE band 20, and the third band is LTE band 5 or LTEband
 26. 18. A module comprising: at least three first filters that areconnected between one first common terminal and a corresponding one ofat least three first terminals, and have different passbands; at leastone second filter that is connected between one second common terminaland at least one second terminal; a first wiring line that connects theone first common terminal to the at least three first filters; and asecond wiring line that connects the one second common terminal to theat least one second filter, wherein the first common terminal and thesecond common terminal are located at a same side as the at least threefirst filters, the at least one second filter is opposite the firstcommon terminal and the second common terminal across the at least threefirst filters, and the second wiring line intersects with the firstwiring line only in a single region.
 19. The module according to claim18, further comprising a ground pattern that is located between thesecond wiring line and the first wiring line located in a region wherethe first wiring line intersects the second wiring line.
 20. The moduleaccording to claim 18, wherein the at least three first filters arelocated at both sides of the first wiring line.
 21. The module accordingto claim 18, wherein the at least one second filter includes at leastthree second filters.
 22. The module according to claim 18, wherein thefirst filter includes a first transmit filter and a first receive filterfor a first band, and a second transmit filter and a second receivefilter for a second band, and the second filter includes a thirdtransmit filter and a third receive filter for a third band, and afourth transmit filter and a fourth receive filter for a fourth band.23. The module according to claim 18, further comprising: a substrateformed by stacking insulating layers, wherein the at least three firstfilters and the at least one second filter are mounted on the substrate,and the first wiring line and the second wiring line are formed onsurfaces of different insulating layers of the insulating layers in aregion where the first wiring line intersects the second wiring line.